Regenerative control for single-phase motors



R. E. HELLMUND."

REGENERATIVE CONTROL FOR SINGLE PHASE MOTORS. APPLICATION FILED SEPT.ma. 1919.

1,41 1,023, v Patented Mar. 28, 1922.

INVENTOR WITNESSES:

QM l d /ff/vd/mund m I ATTORNEY 1 'UNITE'DiSTATES;

aunomr 1'. manual), or swrssvam, rmsnvmu, micron '10 m ne- I noosenaacrmc a mnrac'rumq coxrm, a concur-rumor suvmra 'To all whomit mayconcern:-

Be it known that'I, RUDOLF Ham M'UND, a citizen of the German Empire,and "a resident. of Swissvale, in the county of Allegheny and. State ofPennsylvania, have invented-anew and useful Im rovement in RegenerativeControls 1m Sin e-Phase M05 i tors, of 'whiehthe following is as'pecifica tion. My invention relates to the control of thedynamo-electric machines, and it has spe-f cial relation to theregenerative control o'f single-phase motors employing a phase-converting machine during such operation.

Certain prior. systemsfor' effecting regen erative control in a systemof the above-indicated character, haverequi'red two banks ofhigh-capacity switches and reventive coils,-the one bank for adjustin te voltage of the workingcircuit and t e other for regulating the phaseof the exciting field current. It is one object of my present in ventionto replace the bank of switches corresponding to regenerative 0 erationby a resistance-varying drum of re atively small capacity, whereby amaterial saving in cost and weight of eq g ment is effects Anotherobject i regenerating machine, is adapted to regulate the direct-currentexcitation of a syn throughout a wide range of operation.

, the above-mentioned power-factor relay dechronous 1phase-converterthat .s'upplies energy to t e exciting field mined power-factor may be.maintained Another object of my invention is to provide a switchingdevice in conjunction with "vice and its attendant circuits,.whereby thesively to predetermine I relay device .and'of the excitat on of the.

is varied responmachinearmature voltage (1 f h con itions o t ephase-converter.

My invention may best be understood by reference to the accompanyingdrawing whereln Fig. 1 1s a (1111 ammatlc view of;

the essential circuits o a control system organized in accordance withthe present Specification of letterlvl atent;

my invention is to pro-s vide a system of the class under considera-,tion wherein a relay device, responsive to I power-factor conditlons inthe single-phase winding of the single-phase machine, whereby apredeter- PATENT. OFFICE.

-. comma Ion smoLmrma xorons.

various operating conditions in the system synchronous type, thedirect-current excitation ofwhich from an auxiliary generator 6, may bevaried by means of a pilot-motor-controlled device 7, the movements ofwhich. are responsive to a. power-factor re "lay device ,8. A switchingdevice 9 for vary- 1ng the machine-armature voltage is energized inresponse to certain joint conditions of the power-factor relay device '8and the excitationv of the phase-converter 5, as here- 'inafter'morefully set forth.

The single-phase motor 4 comprises a commutater-ty e armature '11, aconduc-.

tively-connecte neutralizing field windin 12, an interip'ole orcominutating field win ing .13, an a main or exciting-field winding 14 Ihe'phase-converter 5 comprises a rotor 15 whichis provided with asquirrel-cage winding 16..for assisting in the desired inductivetransfer of energy, and also with a field winding 17 that isenergized'from the directcurrent; generator 6 for the purpose of regulatingthepower-factor of the single-- phase 'mach1ne4, in accordance withpreviously known principles.

The rotor 15 is further provided with a shaft 18, whereby thephase-converter may be" started into operation, according to awell-known. 'method. 'The stator of the phase-converter is provided withaprimary winding .19, which 1s connected, through an impedance device20and a movable tap 21, across a section of the supply transformer 5 3,while a tertiary or generating winding 22 is located at right angles totheprimary .winding 19,, as is customary, and is connected, through, aportion 23 ofthe supplyftransforme'r winding and a shiftable tap 24., tothefexciting field winding 14 for the single-phase motor 4. The excltinfield wind- 1ng'1'4 is thus energized, partialy in accordance' with thesu ply-transformer voltage but'chiefly from. t e tertiary windin '22 ofthe phase-converter,- whereby the esired Patented Manes, 1922..Application illed loptember is, ma serial No. seas-11;-

I phase relations, to effect regenerative opbe maintained in which isprovi or, ated surface of the drum,

eration of the single'phase machine'4, may the field-winding circuit.

The auxiliary generator 6 comprises-a .direct-current, commutator-typearmature 26 (led with an operating shaft 27, the shaft being driventhrough any suitable agency, such as asm'all'induction motor (not shown)or a truck axle. A shunt field winding 28 for the'auxiliary generator isconnected throu h a variable resistor 29. A second varifabli resistor30,- different points in which'are connected to a series of controlfingers 31, is connected in circuit with the auxili'ary generatorarmature 26 and the exciting rotor winding 17 of the phase-converter.Consequently, by varying either the resistor 29 in -any suitable manner, or-varyin the resistor 30 by means of U a drum contro er 32, forexample, the excitation of the phase-converter5 may be regw, lated toadjust the-power-factor of the sine operating shaft 33 for the drum controller 32 is suitably secured 'to the commutater-type armature 34 ofthe pilot motor 7, f whichis also winding 35 having two equal sections36 and provided with an exciting field 37 that respectively correspondto reverse and forward operation of the pilot motor. A suitable sourceof energy, such as a storage battery 38-, isprovided in the circuit ofthe pilot motor 7 and the secondary circuits of the wer-factor relay 8,as subsequently traced in detail. r t

The power-factor relay device 8 comprises a commutator-type armature 40,which is energized from the secondary winding 41 of an auxiliarytransformer 42, the primary winding of which is connected in seriesrelation with the armature 11 of the single-phase motor 4. An impedancedevice 44 is also preferably connected in circuit' with the relay devicearmature 40, to allow the desired operating adjustment. The othercomponent element of the relay device, namely, the exciting fieldwindin'g45, is connected across the armature 11 and inducing fieldwinding 12 of the single-phase motor. The cooperating members of therelay device 8 are thus respectively energized in accordance with themachine-armature current and voltage, in other words, the relay device 8is actu in accordance with variations in the machine ower-factor.

Secure to the operating shaft 46 of the relay device 8 is a small drum47, which is maintained'in the illustrated ofi or inoperative positionby means of a centering springs 48. A plura ity of control fingers 49 to53, inclusive, bear upon the I and are adapted to selectively engagecontact segments 54, 55 and 56 when the relaydevice occupies the one orthe other of its extreme positions 6 or lurality of d respectively,corresponding to an increase and a decrease of the active circuit valueof the-resistor 30.

The switching device 9 may take any suitable form, and is here shown ascomprising a solenoid device having a core or plunger 60 thatis suitablyattached to a movable tap 61 in the circuit of the machine-armature 11.,

nections have been made to effect regenerative operation of thesingle-phase machine 4, the operation of the illustrated auxiliardevices 7, 8 and 9 may be set forth as fol ows:

gpon a variation in the power-factor con-' ditions of the single-phasemachine 4, as reflected in the currents traversing the armature 40 andthe field winding 45 of the relay device 8, this device isactuated inthe one or the other direction, for example, into position 2', whereu ona circuit is established rom one termi-na of the storage battery 38throu h conductor 65, control fingers 50 and 51, w ich are bridged bycontact segments 55 of the relay device, conductor 66, fieldwindingsection 36 of the pilot motor 7, conductor .67, armature 34 of the pilotmotor and conductor 68 to the opposite battery terminal. The pilot-motorcontroller 32 is thus actuated in a reverse direction to include acertain increased ortion of the re sistor 30 in circuit, thus ecreasingthe excitation of the phase-converter rotor winding 17, whereby thepower-factor in the restored to the desegment 54, whence-circuit iscompleted,

through conductor 69, field-winding section 37' of the pilot motor andthe armature thereof, to negative conductor 68. In this way, thecontroller 32 is actuated in thei forward direction to graduallydecrease the active circuit value of the resistor 30, and thus augmentthe excitation of the phase-converter rotor winding 17 until the desiredpower-factor conditions in the single-phase machine 4 have beenreestablished.

Further regulation of the machine operation, as regards load and torqueadjustment, may be accomplished by means of the switching device 9.Whenever the resistor-varying drum 32 occupies its extreme right-handposition, correspondin to a com lete exclusion of the resistor 30 iron;circult, provided 1,411,02a-i I Y I I ,3

that the power-factor relay-device Sthen b By subtracting the reversedvectors I assumes its position dcorresponding tofurand E2" from Ea, weobtain ther increase of the phase-converter excita Ef and Ef, whichrepresentthe corretion, the switchin device 9 is then energized spendingvoltages induced I to shift the tran I ormer tapfilftowards the by theconverterfield ri ht, and. thus COIIIPGIISMJIIIglY reduce the I winding17. Thecorrevtitageimpressed upon themachinearmaspending secondary orroture 11. 1 tor'voltagesjin the'phase Such action is accomplishedbylthe'estab-,

lishment of an au xiliar' circuit from-one 3 I by v H terminal of thestorage batter 38 throu h I E8 and E8, which are shifted 90 electrical"conductor 75, magnetizingjwin ing 62 oft e v degrees with respect tothe switching device '9 conductor 76,1 control I j primary voltages.fingers 52. and 53, whichcareibridged by con If the secondary voltagesare f converter are represented,

combined 7 tact segment 56 in position dofthe powerwith a voltage I Y II 5 factor relay device 8, whence circuit is con- Et,'which is derivedfrom the transformer tin'ued'thr'ou h conductor 77, control fingerssection 23, the vectors .7 8 and 79, wl ich are bnidgedb contact seg- EmandEm, epresenting the main or-exment 80 in the above-mentioned extremepociting field voltages are Q sitionof the controller 32, circuit beingcom- I I obtained. These voltages pleted throughconductors 81 and 68 tothe I I induce field currentswhich opposite battery terminal. The conse'uent 1 wla'g approximately be; energization of the actuating coil 62 sifts I I hind "them, which ourthe transformer tap 61 into a voltage-re-I a rents; in turn, induce I 'ducing position; voltages 90 In this way,I have provided a system Er and Er', 'show'n in-Fig. 3, whichreprewherein a smooth and efi'ective control of an ,sent thecorresponding roalternating=urrent regenerative system is i tationalvoltages in the provided without requiring the customary I I phaseconverter. If u I ank of heavy switches for regenerative pur- Eztheimpressed voltage .across the mo- 9 ,poses only, while, at the sametime,v proper tor armature 11 and neutralizing power-factor and torqueconditions in the field winding'12 from the right motor areautomatically maintained. It will hand sectionof the suppl -transbeappreciated that the maintenance of such former 3, the combination 0thoroproper torque conditions in the motor is imtational voltages withthe impressed ortant, s1nce,'whene ver the field and the voltage Eproduces the voltage vecoad current are not substantiall in phase, torsI v the root-mean-square current, an ,therefore,' Ea? and Ed, whichneutralize the resultthe heating of the motor are unduly in ants of thevectors .0 creased. 6i and ei' representing the ohmic drops in Thevector diagrams of Fig; 2 and Fig. 3 the single-phase machinecirillustrate the working principles of the I uit nd j i present inv n ne I I c0 and co, representing the corresponding Eczthesupply-transformer voltage im-' I inductive voltage drops. u pressed p tp ry' v t r I0 and Ie, representing the load currents,

winding 19. i If extendin opposite directions, I:: a leading current andand are proportional to the I:'a lagging current, thenby changingrespective ohmic drops; The the excitation of the phase-conchange fromthe one to the o verter, the value of the input curth tor ag in followrent may be varied from I to I. I alonga straight l ne connect- Iw,representing the power or watt curi in them. rent in the converter, maybe as-' %Jonsequently, by changing sumed as nearly constant, so that thethe excitation of the phase- It change in the total current fromItoconverter, the load current I follows the vertical line connecta of thesingle-phase machine 4 ing the ends of these two vectors. I may bevaried between the E11 and Eizthe primary inductive voltage v valuesrepresented by Ia and drops, which lag 90 be- Ie, and the vector. '0bind the corresponding cur- In, represents the value of load currentrents, I and I Consecorresponding to the desired poweruently, the changefrom -factor.

t e one to theother follows I To accomplish therequired change of load aStraight line between the current without lar e variations in the pri-05 two vectors Eli and mary current of t e phase-converter, the 3 1 withthe primary converter windin impedance device is connected in circuit 19to cause relatively large changes in t e pri- "-";mary inductive;voltage .drops concurrently ,withjsmall current variations.

- by a predetermined specific circuit connections j or. arrangements"of, parts herein set forth',aas-.various modi fic'ationsthereof'ma'ybeefiect'ed without de- 10, ventibmf I; desire, therefore, that onllimitationsishall be imposed as are indi parting' from the spiritandscope of my iii;

suc cated o by the appended claims.

J I claimgas myinventionf 1, In an alternatin g-current regenerativeizystem, the combination with a dynamo- I afield-"producing winding,

' s stem, 1 the 7 combination and phase'relations in the machinecircuits forrelay device for 'said converter.

"relay device having its ectric machine havingflan armature and a t V ofa synchronous phase-converter for exciting said winding,

means responsive 1 to predetermined re lating the excitation offsaidconverter. .In an alternating-current regenerative with a dynamo eectric machine having an armature and a field-producing winding, of asynchronous phase-converter for exciting said winding, and a relaydevice responsive to power-factor conditions in said machine forcompensatingly varying the excitation of said converter. a v j 13. In.an alternating-current regenerative ystem, the combination with adynamoectric machine having an armature and a field-producing-win'ding,of a synchronous phase-converter for exciting said winding,

a relay device having its component elements respectively energized inaccordance with the machine-armature current and volta and meansresponsive to the movements o f said rela device for varying theexcitation of said converter."

4; In an alternat' -c1'irrent regenerative s e ectric machine having anarmature and a field-producing winding, of a synchronous phase-converterfor excitin .said winding, a motor-type relay device having itscomponent elements respectively energized in accordance with themachine-armature current and voltage, and a pilot motor energized to runin the one or the other direction responsively regulating the excitationof 5. In an alternatin -current regenerative a field windin of .aexciting said eld win ing and having a irect-current-excited rotorwindin riable resistor in circuit with sa d rotor winding,'a pilot motorvariation'of said resistor, and a' motor-type component elements yste'm,the :combination with. a dynamo-- to themovements of said' system, thecombination with a dynamo-j ectric 111842111116 hav ng an armature andhase-converter for,

a vafor controlling the tions and 'sponsively to' the respectivelyenergized in accordance with field-producing winding, of a synchronousphase-converter for exciting said winding,

means responsive to predetermined relations in the machine circuits forregulating the excitation of said converter, and means responsivedirectly to said phase relaphase regulating the machine-armaturevoltage. .In an alternating-current regenerative s stem, the combinationwith a dynamoe ectric machine having an armature and a field-producingwinding, of a synchronous phase-converter for exciting said winding, arelay device responsive to power-factor conditions in said machine forvarying the excitation of said converter, and means responsive directlyto the. position of said relay device for varying the machine-armaturevoltage.

8. In an alternating-current regenerative system, the combination with adynamoe ectric machinev having an armature and a field-producingwinding, of a synchronous phase-converter for exciting said winding,means actuated upon a'variation of powerfactor in said machine from agiven value for regulating the converter excitation .to

with the machine-armature current and volt-- age, movable meansresponsive to the position of said relay device for varying theexcitation of said converter, and means responsive jointly to thepositions of said relay device and of said movable means for regulatingthe machine-armature voltage.

10. In an alternating-current regenerative system, the combination witha dynamoe ectric machine having an armature and a field-producingwinding, of a synchronous phase-converter for excitin said winding, amotor-type-relay device Eaving its component elements respectivelyenergized in accordance with the machine armature current and voltage, apilot motor energized to run in the oneor the other directionremovements of said relay motor to vary said indirectly to saidexcitation fordevice for regulating the excitation of said converter,and means ener ized in 'certain, pos1t1ons of said relay device and ofand pilot motor for regulating the machine torque. i

- 11. In an'alternatin -current regenerative system, the combinatlonwith a dynamoectric machine having an armature and a.

field winding, ofa phase-converter for exchine-armature currentandvoltage for en+ ergizingsaid PiIOtiIiiOtO'r tovary said res sister inthe one or the other sense, whereby I a predetermined machine powerfactor may,

be maintained, and a switching device en ergized when and relay deviceoccu ies a predetermined operative position an said. resistor has apredetermlned active value for aetu'atin said switching device to reducethe mac inc-armature voltage, whereb a given machine torque may bemaintaine 12. In an alternating-current regenerative system, thecombination with a dynamo* e ectric machinehaving an armature and afield-producing winding of asynchronous phase-converter for excitingsaid winding,

and means responsive to yariations n predeten nmed" electric quantitiesappertaining to the machine circuits for regulating the e:&- a;

:citation of said converter.

z'I-n testimony whereof I' have hereunto subscribed my .name this 26thday ofg-A'ug. 1919."

RUDOLF E. HELLMUND. I

